Chapter 8 Flashcards
What are the functions of the nervous system
Sensory Function –> Respond to stimuli and generate signals carrying info about stimuli
Integrative Function –> Receive and process info; store and retrieve it; make decisions how to respond
Motor Function –> Issue out-going signals; sends to muscle and gland cells to produce response.
What are the 2 main subdivisions of the Nervous system?
Central Nervous System (CNS) –> Brain and Spinal cord; carries out integrative function
Peripheral Nervous System (PNS) –> Nerves leading to and from the CNS. Provide pathways of signal input/output; connects CNS to body’s sense organs, muscles and glands; carries out sensory and motor functions
What are the functional classification of neurons
- Sensory (Afferent) Neurons –> specialized to detect stimuli and transmit info; travel to brain or spinal cord; most unipolar or bipolar
- Interneurons (association Neurons) –> Perform integrative function; process, store and retrieve information; make decisions about body response; contained within CNS; most abundant neuron type; generally multipolar
- Motor (Efferent) Neurons –> Carry out-going signals from CNS; generally multipolar
What are Neuroglia?
- Perform housekeeping and protective function
- outnumber neurons 10-1
- A.K.A. “Glial” cells
What are the 4 neuroglia cells in the CNS?
1) Ogliodendrocytes –> Produce myelin (insulates the neuron to make it work quicker)
2) Ependymal Cells –> Produce Cerebral Spinal Fluid
3) Microglial –> Small Phagocytic cells which Destroy tissue debris, microorganisms, and foreign matter
4) Astrocytes –> Most abundant in the CNS; form the blood-brain barrier
What are the 2 Neuroglia Cells in the PNS?
1) Satellite Cells –> Insulate Peripheral neurons, insulate them electrically and regulate their chemical environment.
2) Schwann Cells –> Wrap around nerve fibers of the PNS enclosing each in the neurilemma. Spirals repeatedly around nerve, depositing membrane which constitutes myelin sheath. Necessary for regeneration of damaged nerve fibers. NOT POSSIBLE IN THE CNS
What is the Resting Membrane Potential?
When a neuron has a positive charge on the outer surface of the plasma membrane and a negative charge on the inner surface. A starting point for generating a nerve signal.
